Powerful Category 3 Irene enters the Bahamas

Powerful Category 3 Hurricane Irene stormed through the Turks and Caicos Islands overnight, bringing hurricane-force winds, torrential rains, and storm surge flooding. On Providenciales in the Turks and Caicos Islands, where half of the population of these islands live, winds reached a sustained 65 mph at a personal weather station at Pine Cay, and the pressure bottomed out at 989 mb. The eyewall of Irene missed the island, with the center of the storm passing about 60 miles to the southwest. The center of Irene passed about 60 miles to the northwest of Grand Inagua Island, and Category 1 hurricane conditions were probably experienced on that island. Damage in the Turks and Caicos is likely to be much less than the $50 - $200 million wrought by Category 4 Hurricane Ike of 2008, since Irene's eyewall missed populated islands.

Figure 1. Morning satellite image of Irene.

Monday, Irene hit Puerto Rico as a tropical storm with 70 mph winds, but reached hurricane strength as it emerged into the Atlantic northwest of the capital of San Juan. One drowning death is being reported from the island, and the storm dumped up to 20 inches of rain in some areas. About 11% of the island was still without power this morning, and numerous roads were closed due to flooding and landslides. Irene did an estimated $17 million in damage to agriculture and $2 million to ports in Puerto Rico. Satellite estimates suggest that Irene has brought only 1 - 2 inches of rain to Haiti. With Irene now pulling away from Hispaniola, Haiti can expect only another 1 - 2 inches from the hurricane, and appears to have dodged a major bullet. Heavy rains of 3 - 6 inches were common across the Dominican Republic, where moderate flooding but no deaths occurred.

Track forecast for IreneContinuing dropsonde missions by the NOAA jet have helped to significantly narrow the uncertainty in the 1 - 3 day forecasts from the computer models. Irene will track through the central Bahamas today, the northwestern Bahamas on Thursday, and approach the Outer Banks of North Carolina on Friday. However, the models still diverge considerably on their 4 - 5 days forecasts, and we don't know if Irene will plow up the mid-Atlantic coast into New Jersey, as the GFDL model is predicting, hit New England between Long Island, NY and Massachusetts, as the ECMWF, GFS, and HWRF models are predicting, or miss the U.S. and hit Canada, as the NOGAPS model is predicting.

Intensity forecast for IreneLatest data from the Hurricane Hunters shows that Irene has paused in its intensification cycle. A gap has opened in the eyewall, and the central pressure has remained constant at 956 - 957 mb over the past few hours. However, the hurricane is embedded in a large envelope of moisture, and wind shear is expected to remain low to moderate, 5 - 20 knots, for the next three days. With water temperatures very warm, 28 - 30°C, these conditions should allow for intensification to a Category 4 storm sometime in the next two days. Satellite loops show that Irene is well-organized, with excellent upper-level outflow, and impressive spiral banding.

Irene's impact on the Bahama IslandsIrene is making a direct hit on Crooked Island (population 350) in the Bahamas, and will continue west-northwest and hit Rum Cay (population 80) and Cat Island (population 1700) late tonight. These unfortunate islands will bear the full brunt of Irene's 115+ mph winds and 8 - 13 foot storm surge, and suffer major damage that will take months to recover from. Major damage is also likely on Long Island (population 3000) and San Salvador Island (population 1000.) Shortly after midnight tonight, winds at the capital of Nassau, home to 70% of the population of the Bahamas, will rise above tropical storm force, and increase through the night. By late morning on Thursday, sustained winds will peak on Nassau at just below hurricane force, 60 - 70 mph. Nassau will miss the brunt of the storm, and I expect the airport should be able to re-open on Friday. Winds on Grand Bahama Island in Freeport will rise above tropical storm force late Thursday morning, and increase to a peak of 45 - 60 mph late Thursday afternoon. Grand Bahama will also miss the brunt of the storm, but Abaco Island to its east will likely experience Category 2 hurricane conditions Thursday afternoon. However, Abaco will probably miss the right front eyewall of Irene with the strongest winds and highest storm surge.

Figure 2. Wind distibution around Irene as of 1330 UTC (9:30am EDT) August 24, 2011. Irene was a Category 3 hurricane with 115 mph winds at the time. Hurricane force winds (yellow colors) extended over Crooked Island to the storm's northwest, and over Mayaguana Island to the east. Image credit: NOAA/AOML. Irene is a large storm, and its potential storm surge damage rated 3.9 on a scale of 0 to 6, with its wind damage potential rated at 2.5 on a scale of 0 to 6.

Irene's impact on the Southeast U.S. Long-period ocean swells from Irene will reach the coast from Florida to North Carolina tonight, and continue to build as the storm approaches. The outermost rainbands of the hurricane will reach South Florida by Thursday morning, and spread over much of the eastern coastal portion of Florida during the day Thursday. If Irene follows the official NHC forecast through the Bahama Islands, the storm's expected radius of tropical storm-force winds of 130 - 170 miles will keep tropical storm conditions just off the east coast of Florida. Sustained winds of 20 - 30 mph can be expected along the coast of Florida during Irene's point of closest approach, and rainfall amounts of 1 - 2" will be common along the coast. Georgia, which could use the rain, will get very little. It is unlikely any airport in Florida or Georgia will need to close for Irene.

Late Friday night or early Saturday morning, Irene's outer spiral bands will move over the southern coast of North Carolina and the northeastern portion of South Carolina, and tropical storm-force winds of 39+ mph will arrive. Winds will steadily increase to hurricane force on the Outer Banks by Saturday night. The main damage from Irene in North Carolina will come from the storm's flooding rains of 4 - 12" that will fall in coastal areas. Fortunately, this region is under moderate to severe drought, so the damage will not be as severe as that experienced during Hurricane Floyd of 1999. Significant wind damage can be expected in the Outer Banks of North Carolina, and considerable storm surge damage may occur along the shores of Pamlico and Albemarle Sounds. If Irene's eye misses making landfall in North Carolina, total damage from the storm should be less than $200 million, and could be considerably less than that.

Figure 3. Sea surface temperatures for August 24, 2011. Temperatures of 26°C (79°F) are typically needed for a hurricane to maintain its strength (black line). This boundary lies just off the southern coast of New Jersey this year, which is much farther north than usual.

Irene's impact on the mid-Atlantic and New England The impact of Irene on the mid-Atlantic and New England is highly uncertain at this point, because we don't know if the core of the storm will miss the coast or not. In general, the heaviest rains will fall along a 100-mile swath just to the west of where the center tracks, and the worst wind and storm surge damage will occur to the east. If the core of Irene stays offshore, the mid-Atlantic and New England may escape with a few hundred million dollars in damage from flooding due to heavy rains and storm surge. If Irene hits Long Island or Southeast Massachusetts, the storm has the potential to be a $10 billion disaster. Irene is one of those rare storms that has the potential to make landfall in New England as a Category 2 or stronger hurricane. It is difficult for a major Category 3 or stronger hurricane crossing north of North Carolina to maintain that intensity, because wind shear rapidly increases and ocean temperatures plunge below the 26°C (79°F) level that can support a hurricane. We do expect wind shear to rapidly increase to a high 30 - 50 knots once Irene pushes north of Delaware, which should knock the storm down by at least 15 - 30 mph before it reaches New England. However, this year sea surface temperatures 1 - 3°F warmer than average extend along the East Coast from North Carolina to New York. Waters of at least 26°C extend all the way to Southern New Jersey, which will make it easier for Irene to maintain its strength much farther to the north than a hurricane usually can. During the month of July, ocean temperature off the mid-Atlantic coast (35°N - 40°N, 75°W - 70°W) averaged 2.6°F (1.45°C) above average, the second highest July ocean temperatures since record keeping began over a century ago (the record was 3.8°F above average, set in 2010.) These warm ocean temperatures will also make Irene a much wetter hurricane than is typical, since much more water vapor can evaporate into the air from record-warm ocean surfaces. The latest precipitation forecast from NOAA's Hydrological prediction center shows that Irene could dump over 8 inches of rain over coastal New England.

Figure 5. Soil moisture profiles from yesterday show that a region of very moist soils ranking in the top 1% in recorded history (dark green colors) lie over northern New Jersey, Southeast New York, and Northeast Pennsylvania. Image credit: NOAA/CPC.

Tropical storm-force winds and heavy rains will move into Eastern Virginia Saturday afternoon, and push northwards to Delaware and coastal Maryland by late Saturday night. Tropical moisture through a deep layer of the atmosphere will also stream well ahead of Irene into New England on Saturday afternoon and evening, bringing what is called a "Predecessor Rain Event" (PRE). The Washington D.C., Baltimore, and Philadelphia airports will be right at the edge of the heavy rain and high wind area, and it currently appears they will not have to close for an extended period. The Philadelphia and New York City airports may not be as lucky, and it is possible they will suffer extended closures Sunday morning and afternoon. By late Sunday night, Irene's rains will move north of New York City, allowing the airports to re-open. The highest potential for damaging fresh-water flooding is in northern New Jersey, Southeast New York, and Northeast Pennsylvania, where soil moisture is near record high levels, and there is nowhere for the rain to go (Figure 5.) Heavy rains of 4 - 12" are likely across all of coastal New England if Irene passes within 100 miles of shore.

LinksFor those of you wanting to know your odds of receiving hurricane force or tropical storm force winds, I recommend the NHC wind probability product.

Elsewhere in the tropicsA tropical wave far out in the eastern Atlantic about 200 miles southwest of the Cape Verde Islands, Invest 90L, is showing signs of organization. NHC is giving this disturbance a 50% chance of developing into a tropical depression by Friday. Several of our models do develop 90L into a tropical storm by early next week, but long-range models are showing that this system will not be a threat to any land areas over the next seven days, and will probably move too far north to ever be a threat to land.

Internet radio show on Irene at 4:30pm EDT todayI'll be discussing Hurricane Irene on a special edition of our Internet radio show, the Daily Downpour, today (Wednesday) at 4:30pm EDT. Fellow wunderground meteorologists Shaun Tanner, Tim Roche, and Angela Fritz will also be there. Listeners can email in or call in questions. The email address to ask questions is broadcast@wunderground.com.

Pick any NHC satellite animation of Irene and enable the check for Trop Pts and watch how Irene is exactly in line with the NHC's forecast points. I think they have this one nailed. I would follow whatever the NHC puts out and not put so much into the models going West or going East, let the experts at the NHC handle that, they seem to have it figured out quite well!

Is it just me, or are a number of models pushing back slightly to the west? I'm in West Palm Beach, so a slight westward move could spell the difference between simply a blustery day tomorrow or tropical storm conditions. Thoughts?

At 18:00 PM UTC, Tropical Depression (1002 hPa) located near 16.6N 141.8E has 10 minute sustained winds of 30 knots with gusts of 45 knots. The depression is reported as moving north northwest at 6 knots

Of the big 4 models the GFDL is still trending some west, which has been the case for years. I dont think it will go as far west as Wilmington right now but its really to hard to say depending on the EWRC and the ridge over the US. The biggest question in steering is will Irene find that area or is Irene too far south to feel that or will that ridge over the US erode?

Earlier in the week, the consensus was that the ridge was too weak. Well, I have to still agree with that somewhat based on what I am seeing. I remember watching a storm last year that was aiming right at the Carolina's and it skirted off the coast in a very similar situation but it tracked slightly west of the original track.

Lots of debate on the track of that storm went on for days (like what we are currently seeing) but in the end, the storm did react slower and it did go a little further west.

I am trending more to a Wilmington area landfall...and again, my opinion.

Okay thanks!! I tell you, people I have talked to here are thinking this is going out to sea..if this comes even closer than the TS force winds than what they are predicting, you are going to have a lot of people caught off guard here in Wilmington

Looks like the models are now saying Florida will even dodge the rain from from Irene. As it will tap into the lower dewpoint air currently over central Georgia and bring it on down the spine of the Peninsula.

Well put Minnemike! So how's the weather up there! Grew up there and landed in Florida after the Air Force sent me to Spain and Florida. Still a diehard Vikings fan as you can probably tell! Interesting to see someone living in MN on a Tropical Storm blog but then again Levi is from Alaska!

it is a TRULY gorgeous day up here!!! can't wait to get back out when shift is over :D

..my big interest is severe plains weather. in 2006 i started checking out WU resources, and when the stormy season up here ended, the tropics were just gettin cooking!! started reading Dr. M's posts, lurked and learned from a few folks here, then got me a handle and joined the fray ;)

No problem...just checking. It's been a long time since both! lol...The details of each storm get lost over time. With Hugo I just think about the powerless 3 weeks and huge mess to clean up, and Floyd I remember because I donated tons of money to my church for teams to rebuild after the flooding well up to even 2 years later. Floyd was a GREAT example of how much damage a large in diameter Cat 1 can do when it slows/stalls as Floyd did. Nonetheless...you seem quite confident so I'm sure your memory is better than mine!

Actually Hodges was Gov for Floyd. And he took a lot of heat for the evac debacle.

savanah was evact for hugo later in the models approximatley 600 miles out savanah was thought to be hit point . i made comment on the outter banks because this far out it was suppose to recurve and skirt the outter banks then later when storm was 600 miles out the models thought savanah . see what im talking about ,models are a tool nothing else . when storm was 400 miles out it turned like i was trying then to tell those reading these post that charelston was more likely . never mind there are way too many people that will follow like cattle to the slaughter I wont post again till tommarow see ya . have a good one dew

H.Irene's_6pmGMT_ATCF : Starting 23August_6pmGMT and ending 24August_6pmGMT The 4 eastern line-segments represent HurricaneIrene's path("5": the line segment connecting the latest 2 coordinates was bisected by passage through AXP) and the westernmost line-segment is the straightline projection.

Using straightline projection of the travel-speed&heading derived from the ATCF coordinates spanning the 6hours between 12pmGMT then 6pmGMT :H.Irene's travel-speed was 14mph(22.5k/h) on a heading of 310.9degrees(NW) H.Irene was headed toward passage over McKanns and Bowers(LongIsland)Bahamas ~3&1/3 hours from now

I know that is what they are doing one of them mailed me on here earlier today and said they were going to team up to remove all my posts. Then they had the nerve to tell me that I should go sit on the beach because my days were numbered anyway with or without a storm.

How exactly did they propose to do that? Are they admins fro thi ssite, or just magical? Gpa24, they were trying to get your goat

TWC last time I looked was blowing up the NYC storm and I just went on Allan's page and the links wont work? which model has trended back west?

Of the big 4 models the GFDL is still trending some west, which has been the case for years. I dont think it will go as far west as Wilmington right now but its really to hard to say depending on the EWRC and the ridge over the US. The biggest question in steering is will Irene find that area or is Irene too far south to feel that or will that ridge over the US erode?

Earlier in the week, the consensus was that the ridge was too weak. Well, I have to still agree with that somewhat based on what I am seeing. I remember watching a storm last year that was aiming right at the Carolina's and it skirted off the coast in a very similar situation but it tracked slightly west of the original track.

Lots of debate on the track of that storm went on for days (like what we are currently seeing) but in the end, the storm did react slower and it did go a little further west.

I am trending more to a Wilmington area landfall...and again, my opinion.

The Canadian intensifies the polar vortex and has it building NW in a retrograde fashion. Their tropical solution is goofy, but they are very strong on polar/sub polar synoptic weather. The original GFDL track is not out of the question (Delaware\NJ\Adirondacks).

I know that is what they are doing one of them mailed me on here earlier today and said they were going to team up to remove all my posts. Then they had the nerve to tell me that I should go sit on the beach because my days were numbered anyway with or without a storm.

Quoting JeffM:I get the feeling that Bastardi's favorite model is the one that agrees with his track forecast. Doesn't matter which one it is, as long as it does the most damage to the East Coast.

Yes, you are right. Also, he'll start saying a big impact storm to the Northeast will start up the "global Warming" matter and he'll complain about it for weeks proving that the world is cooling and ice is growing in the poles. If I can remember from last week, he said Irene was a Florida storm. I call that a bust.

nope...campbell was gov during HUGO...BEASLEY was gov during FLOYD, beasly would NOT open the east bound lanes of I26, said we never did it before...Harve Jacobs from Channel 5 news got the footage from hugo and took it to Beasly in Columbia before Floyd got here and played it for him to PROVE Campbell had done it...besides...i SAYED for hugo and had to EVAC for Floyd...i did not take I26 for Floyd...i went out hwy 61 toward summerville...i can give you a link to where savannah was evaced for HUGO

No problem...just checking. It's been a long time since both! lol...The details of each storm get lost over time. With Hugo I just think about the powerless 3 weeks and huge mess to clean up, and Floyd I remember because I donated tons of money to my church for teams to rebuild after the flooding well up to even 2 years later. Floyd was a GREAT example of how much damage a large in diameter Cat 1 can do when it slows/stalls as Floyd did. Nonetheless...you seem quite confident so I'm sure your memory is better than mine!